Refrigerant plates



June 9, 1959 H. W.KLEIST 2,389,694

REFRIGERANT PLATES Filed Jan. 9, 1957 s Sheets-Sheet 1 2'1 zz 1% L 24yfafl'er" Carter afltiorneys June 9, 1959 H. w. KLEIST REFRIGERANTPLATES 5 Sheets-Sheet 3 Filed Jan. 9, 1957 fnveiz for Jzerman WI/ez'SZ5y jar/fer & Carafe flizorieqys 2,889,694 I REFRIGERANT PLATES Herman W.Kleist, Hollywood, 111., assignorto' Dole Refrigerating Company,Chicago, 111., a corporation:

of Illinois Application January 9, 1957, Serial N0. 6 3 3, 2 9 9tClaims. (Cl. 62-439) My invention relates to an improvement in heatlexchange plates, and has for one purpose to provide a tor passagestructure formed of sheet metal.

Another purpose is to provide a heat storage which a rolled or stampedcoil component is combined an eutectic in heat exchange relation withthe coil.

plateiofi the type used, for example, in truck refrigeration, in

. A the: the shownafor example;

in R sin 5 and 6,are as semb1ed--to;fonn a-water-tight. and gas;tightg-container. Withintthe container or. housing .,so; formed Iprovide the 1 spacing structure wall, shown, for examplepinFigures 3,.6Jand 7. a I employ, for, example,

- 1 aplurality of channels, generally indicated as 6 ,which;

have parallel flanges6a, 6b :connected'by ,-a..cross-piece 6cvTlhe:scross-piece;-6c,as shown in Figures; 3 1 andp8,, are penetrated byaperturesl6d2The flanges 6aand-. 6b are penetrated by apertures or; gaps6a,, the purpose of;

, which will=later appear." Itwillbeunderstoodtthatethew channel members6sare arranged with their free. edges, ofthe flanges fia and6blabuttin'g the inner surface of the; plate side walld, while theconnecting'portions or webs'" 6c abut the later described coil of thecoil assembly -A.'

:.';1. As: win-ms clear from Figuretiip the channels; 6 arezof-i plateof the type used in refrigeration, which is eff c ent in use, strong instructure, and simple to manufacture.

Another purpose is to provide a heat exchange platev which includes apressed or rolled metal coil or evapora varying 1 length"; since somefree inside space'*within: thei P ate is I finditadvantageous jfo"employ twotypes of spacers or positioning' members-to ntake sure that"the spacing channels '6 are themselvesarranged in' desired' relationAnother purpose is to provide such aplate in which various parts of theplate are held or urged together .by a pressure differential between theinterior and the esterior of the plate.

Other purposes will appear from time totimein course of thespecification and claims.

I illustrate my invention more or. less clia'grammatically in theaccompanying drawings, wherein:

Figure 1 is aplan view; a, Figure 2 is a side view of the structure ofFigure 1;-

Figure 3 is a view of the interior of the plate with the shorter of thespacing fins or channels 6, and thus serves ship' within the plate.basic type-"of spacer or bracket" is shown, -for'exarhple, in Figured;and is shownin posi-" tionat various' points'in Figure 3; Thesebrackets7 have end flanges 7a connected by perpendicular portions" 7b with theintermediate body portion 70. The spacer flanges 7a either abut one ofthe circumferential edge wall portions 4 or else abut the special spacerbody illustrated as 8 in Figure 4. This spacer 8 has at one end a flange8a abutting one edge wall 4 and at the opposite end, and at right anglesto the flanges 8a, a flange 8b which abuts another of the edge wallportions 4. The spacer or bracket 8 is shown in position at the lowerright hand corner of Figure 3, and receives the ends of the to keep anopen space, indicated as C, within the plate.

Figure 6 is a section on the line 6-6 of Figure the specification anddrawings.

Referring to the drawings, and, for example, to 6, A refers generally toa preferably. rolled sheet metal coil structure, and B refers to therest of the plate. With reference now to the general showing of Figures1, 2, 6 and 7, the coil assembly is formed of two sheet metal layers,indicated, for example, at 1 and 2 in Figures 6 and 7. Whereas, in thesefigures a separation is indicated be: tween the layers 1 and 2, it willbe understood that in the manufacture of the rolled coil the metal maybe so closely bonded together, where the two sheets abut, ,as toevidence no visually observable separation between the two layers. It isthought best, however, to illustrate the two layers in the drawings asshown, that the method of making the plate may be the clearer.

Before further describing the coil, it will be well to point out thatthe coil assembly A serves as one side of a plate interior in which asuitable eutectic may becontained. The plate is formed, for example, ofaplanesurfaced side wall 3 having circumferentially extending edgeflange or flanges 4 which terminate at their upper outer edges inoutwardly extending flange portions '5. These flange portions 5 abut,and may be welded or otherwise secured to the marginal portion of therolled coil assembly A. It will be understood,'of course, that t Likeparts are indicated by like symbols throughout The individual channelsare spaced apart by use of the brackets 7, as illustrated in Figure 5and as shown in position in Figure 3. By the spacers and brakets abovedescribed the spacing channels 6 are uniformly or substantially arrangedwithin the plate in their desired relationship to the plate side wall 3and the coil assembly A. The free space C leaves room for the laterdescribed fittings. Since the height of the brackets or spacers 7 and 8is less than the height of the interior of the plate there is nodamaging interference with the movement of eutectic within the plate. Itwill be understood that the spacers may be fixed in position in anydesired manner, or may be merely inserted loose, since they cannotescape from their assembled position. The aperture 6d permits therelatively free flow of eutectic throughout the interior of the plate.

Considering, next, the coil assembly A, it will be understood that inthe formation of the coil the two sheet metal plates or layers 1 and 2are fed between appropriately formed rollers by an already knownprocedure, not of itself part of the present invention, to produce thefinal coil. In practice, the two sheets of metal are trimmed to propersize and dimensions and are rolled to bond the two sheets togetherexcept along the contours of the desired coil. 'The result is acomposite sheet in which the layers 1 and 2 are bonded togetherthroughout a substantial part of their area, but are separated in suchfashion as to define a coil pattern. Along this coil pattern the twosheets are rather widely separated, as shown at la and 2a in Figure 6.In the present plate the pattern includes a length 9 along one side ofthe plate which connects to a length 10 along one edge of the plate anda length 11 along the opposite long side of the plate. Beyond the length11 is a series of straight stretches 12, the length 11 and thesuccessive lengths 12 being 0011- nested together by arcuate'bends orconnecting portions 132 Thelast straight stretch 12 terminates with n 90curve 14 which, in turn, extends by a straight section 15 which is atright angles to the length 11 and 12. The

initial stretch 9 is connected' by a90- bend -16 to the edgeofthe plate.The above coil structure may, for-example, be-madeof two sheets ofaluminum.- Inth'atevent, I findit advantageous to weld coppertubingfittingsas shown at 17' and 13. To these'fittingsany-suitableputside connecting ducts or pipes 19 and 20 may besecured.

Assumethat the coil elements A, formed as above described, andproperlytrued and flat, has been seam-welded or otherwise secured to theflanges Siof the edge walls 4; The parts are soproportioned that theinwardlyprojectingcoil portion 2a abuts the webs 6c of the spacing.

channels 6. The space about thechannelsand between the side wall 3 andthe coil assembly A may be substantially filled by a suitable eutectic.This eutectic may, for

example, be filled through'any suitable;fillingplug.orv

fitting, more or less diagrammatically indicated at 21 in Figures land2. Assumctlrat the interiorof theplate has been substantially filled oradequately filled with a suitableeutectic, it is'important to maintaina. proper heat exchange relation between the coil and the spacingchannels d, and to prevent any tendency of the plate to take a; damagingbulge, due to successive freezing and thawing of the eutecticwithinthe-plate. I find it highly advantageous to withdraw air from theinterior of the plate. and thus to maintain a lessthanaatmosphericpressure within the plate. As a result of this less-than-atmospheric'pressure the outside atmospheric pressure firmly urges the coilassemblyA and the plate side wall3 togetherabout the-spacingchannels 6. Thus'theedgesofthe flanges fizz/and 6b abut the inner surface of the plate sidewall}, and the webs 6c firmly abut the inwardly projecting coil portion2a. 1 find it advantageous to withdraw-the air. from within the platethrough a suitable fitting illustrated at 22 in Figures 1 and. 2. Thisfitting may include. a

check .valve in the form of a ball 23', and may further. have an outsidescrew closure or plug 2.4. After the plate hasbeen adequately filledwith the eutectic 'itjs preferably placed. on edge, and asuitableproportion of, the'air with- 'in the plate is withdrawn.Thereafter the outside plug 24 may be put in position, and ,thererwillbe no escape of 1 air. into the interior of the plate. The pressuredifierem tial between the interior of the plate and the amblent anoutside may be widely varied within reasonable limits.

An internal negative pressure of two or three inches of vacuum may beadequate in some circumstances. In other circumstances, ten or fifteeninches of vacuum, or more, may be drawn. With thin aluminum sheets;however, it is undesirable to employ too high vacuum, sincesome ripplingof the sheets, between edges or points of support, may take place.

Itwil-l be understood that my plate may be used in a variety of heattransfer situations, including both refrigeration and heating. However,I find it particularly adaptable for service as a plate used inrefrigeration. Under such circumstances I find it important to have atleast one illustrated a practical and operative device, nevertheless:

many changes may be made in the size, shape, number and disposition ofparts without departing from the spirit of my invention. I thereforewish my description and drawings to be taken as ina broad senseillustrative or diagrammatic rather, than. as limiting me to my preciseshowing herein.

assesses The use and operation of the invention are as follows:

I provide a plate, the coil element of which can ad vantageously be madeby roll bonding. This is particularly the case where aluminum sheet isemployed. The coil thus formed may be light in gauge and relativelyflexible. I find it important to provide adequate supporting and spacingmeans for the coil, in applying it as a component to an eutectic orhold-over plate. In practice, it is important that no spacing means bedirectly secured or welded to the coil component. I find it advantageousto maintain a spacing structure within the plate, in the form, forexample, of a plurality of spacing channels above described. Thisspacing structure is proportioned to fit snugly within the plate, andthe partial exhaustion of the air from the interior of the plate isemployed to urge the opposite plate side wall toward the coil struc turewhich forms one side wall of the plate. The points or planes of supportare sufiiciently numerous to provide a substantial uniformity of platedimension. The spacing channels abut the coil-in good heat transferrelation and,- in turn, maintain adequate temperature transfer'area within the eutectic toform, in effect, an extension or a fin system for the.coil which extends throughout the eutectic body, while being providedwith-sufficient apertures to permit the circulation 'or movement of theeutectic within the plate interior.-

I claim:

1. In asheet metal plate for refrigeration-and-the-like,

a generally fiat sheet metal plate side Wall, a secondplatesidewallspaced therefrom and generally parallel therewith, edge wallsconnecting said side walls and sealed thereto'to forma gas-tightenclosure about the interior ofthe plate thus formed, said second sidewall being constitutedby two .sheetsof metal bonded together, thesheetsbeing generally plane, but being each deformed from such plane to definea sinuous coil located within the periphery of the two sheets, but withthecoil having two ends extending to and open at the edgeof the plate;inlet and outlet fittings for said coil ends, a spacing assembly looselypositioned in theinterior of the plate, and means for maintaining theinterior of the plate at a less-than-atmospheric pressure and forthereby causingthe excess exterior pressure to urge the plate side wallsinwardly against such spacing means and into satisfactory heat transferrelation therewith, the interior of the plate being substantially filledwith a eutectic.

2. The structure of claim 1 characterized in that the second plate sidewall is formed of aluminum sheets, theinlet and outlet fittings being ofcopper.

3. In a sheet metal plate for-refrigeration and the like,

a generally fiat plate side wall, a second plate side wall spacedtherefrom and generally parallel therewith, edge walls connecting saidside walls and sealed thereto form a gas-tight enclosure abouttheinterior of the plate thusformed, said second side wall beingconstituted by two sheets of metal bonded together but deformed fromeach other to define a sinuous coil located within the periphery of thetwo sheets, inlet and outlet fittings for the coil ends, anda-spacingassembly loosely positioned inthe interior of the plate, said assemblyincluding a plurality of separate'channels' positioned to abut thesecond side wall with the edges of thechannels abutting thefirstsidewall, and additional spacing members within the plateformed-and positioncd to space the channels apartand to maintain thechannels in-apredetermined position within the plate interior, and meansfor maintaining a less-than-atmospheric pressure in the interior spaceof the plate, whereby outside atmospheric pressure is caused to maintaina thrust of the plate side walls toward eachapart and for maintainingthem in a predetermined position within the plate interior.

5. The method of making a refrigeration plate which includes forming abonded coil assembly by bonding two sheets of metal together Whilespacing them apart along a pattern defining a coil having an inlet andan outlet aperture open at the edge of the coil assembly, forming asheet metal plate side wall with circumferential edge wall portionsterminating in outwardly extending flanges, positioning between theplate side wall and the coil assembly a plurality of loose spacingelements, positioning these loose spacing elements in a predeterminedrelationship to each other, welding the said flanges to the edges of thebonded coil assembly at a point exterior to the coil pattern, thereaftersubstantially filling the interior of the plate with an eutectic, andthereafter partially exhausting the interior of the plate, and sealingsaid interior, while maintaining the interior of the plate at aless-than-atmospheric pressure, and thereby causing the outsideatmospheric pressure to urge the bonded coil assembly and the plate sidewall toward each other and against the spacing elements.

References Cited in the file of this patent UNITED STATES PATENTS2,145,308 Jordan et a1. Jan. 31, 1939 2,416,015 McGufiey Feb. 18, 19472,638,754 Kleist May 19, 1953

